1. Field of the Invention
The present invention relates to a TOC recording/reproducing device provided with a recording medium operable in two different directions, such as S--DAT (Stationary-head Digital Audio Tape Recorder).
2. Description of the Related Art
In recent years, digital technology has been applied to a large number of technical fields such as acoustics and image processing, and techniques relative to players, R--DATS (Rotary-head Digital Audio Tape Recorder), digital VTRS, etc. have been developed. Among them, the technique of pursuing comfort for use, such as high speed search, as well as the basic technique of recording/reproducing PCM signals have become important.
Among the high speed search techniques, attention has been paid to the method named `TOC` (Table of Contents) in which the beginning of a desired musical piece is searched and reproduced using a table of base (head) addresses of musical pieces.
The conventional search method using TOC is disclosed in e.g. "JAS Journal" published by Nippon Audio Association, Nov., 1987, pp. 26-27.
An explanation will be given of the conventional high speed search method.
FIG. 10 shows a record of the tape for realizing the conventional high speed search. A TOC recording area named `U--TOC`, where a user can record, is located at the starting end of the tape. The U--TOC area is succeeded by audio data which is divided into units called programs. Usually, one musical piece corresponds to one program. Each program is numbered by a corresponding `program number`. The absolute times indicative of the absolute addresses on the tape are recorded on the tape.
The format of the absolute time and TOC in DAT system is described in "DIGITAL AUDIO TAPERECORDER SYSTEM" published by DAT Conference, Jun. 1987, pp. 72-77.
An explanation will be given of the method of searching a program number using TOC.
When a cassette is inserted into a reproducing device, the U--TOC area at the tape starting terminal is searched to read TOC to be stored. Thereafter, if a direction of searching a program number is issued, the absolute time indicative of the head of the directed program is read from the stored TOC, thereby searching the position on the tape on which the absolute time has been recorded. Since the absolute times have been continuously recorded on the tape, if a user carries out the high speed search while reading the absolute time to compute the difference between the current position and a target position and earlier decelerate the speed, he can realize the optimum speed control. Thus, the time taken for the program search can be shortened. However, the conventional TOC recording/reproducing device, in which the TOC data is recorded only at the starting terminal of a tape, takes a relatively long time to initially read first.